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Science Binder Contents The following items must be in the binder and in this order: Title page Research paper Bibliography Abstract –this is done after the experiment Research Plan Purpose Hypothesis Materials Procedure Data Results Conclusion ISEF forms Journal Pictures

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Once you type everything for the binder, you’ll print each page twice. One copy for the binder The second is modified a little for the backboard

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For those selected to go to the Diocesan Science Fair: The title page can not have your name on it. You will have to reprint the title page. Therefore, please save all typed pages in a file and backup to flash drive. Your name can go on the back cover of your binder.

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Abstract The purpose of this project was to investigate the effect of different amounts of acid on the curdling process of milk. This was accomplished by experimentation and comparative studies. For my experiment, I used four different types of milk: skim, 2%, whole, and whipping cream. For each milk type, I heated the milk, poured the same amount into five separate containers, added different amounts of lemon juice (acid) to each sample, allowed the milk to cool, poured the milk through a cheesecloth to separate the curds from the whey, allowed the samples to dry overnight, and weighed the curds left on the cheesecloth. My hypothesis for this project was that the higher the acid content of the milk, the quantity of curds produced would be higher. Higher milk fat contents should also increase the amount of curds produced. The constants and controls in my experiment were the amount of milk used and the temperature the milk was heated to. The variables in my experiment were the amounts of acid added to the milk, and the different types of milk used. The results of the experiment showed that when more lemon juice was added to the milk, more curds were produced. The experiment also showed that higher milk fat contents produced more curds. The results show that my hypothesis was correct. If I were going to do this experiment again in the future or expand this experiment, I would put more lemon juice in the milk and keep Increasing it to try to determine the maximum amount of curds that could be produced. Writing the Abstract Follow handout provided earlier in the year.

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Research Plan The problem: The purpose of this project is to investigate the effects of different amounts of acid on the curdling process of various types of cow’s milk. Independent variable: different types of cow’s milk and different amounts of acid Dependent variable: the amount of cheese produced due to the curdling process of the milk with the acid Controls: the amount of milk used and the temperature the milk is heated to Quantitative measurement: weight (in grams) Experimental and control groups: The control group for each milk type is the cup with zero lemon juice added. The experimental groups are the varied amounts of lemon juice added Materials: skim milk, 2% milk, whole milk, whipping cream, lemon juice, tap water, whisk, saucepan, thermometer, cheese cloth, strainer, scale, measuring cup, 21 plastic drinking cups, 5 clothespins, hanger, newspaper, and Sharpie pen. The different milks, cheese cloth, and lemon juice will come from the grocery store. The kitchen items are from my kitchen. The scale is borrowed from my dad’s engineering company. Procedure: For each of the different milk types, the following steps were followed. Divide the cups into sets of five and label 1, 2, 3, 4, and 5. Weigh the empty cups and record in journal. Add 3 1 / 3 cups of milk into saucepan and heat on stove top to simmer (195° F) while stirring with a whisk to avoid milk from burning. When 195° F is reached, remove saucepan from stove top and pour warm milk into each of the cups to the mark. Weigh cups again and adjust as necessary so that the weight of milk in all cups is 150 grams. Subtract the weight of the empty cups from the weight of the cups with the milk to provide the weight of the milk. Add 0, 15, 25, 40, and 55 drops of lemon juice to cups 1 through 5 and swirl. Allow the milk to cool for about 1½ hours. Meanwhile, cut the cheesecloth into equal sizes, and weigh each piece. After the milk has cooled, place a piece of cheesecloth (folded over once) into the strainer, and pour the milk over the cheesecloth so that the whey passes through, but the curds do not. Fold the cheesecloth containing the curds up from the corners, and hang the cheesecloth with a clothespin on a hanger to allow the whey to continue to drain out onto newspaper overnight. Weigh the cheesecloth with the curds. Subtract the weight of the cheesecloth to provide the weight of the curds obtained. Writing the research plan: Please follow the handout provided

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Hypothesis: For each of the different milk types, the more drops of acid that are added, the more curds will be produced. Also, the higher the percent milk fat, the amount of curds produced will increase. Research explanation: My hypothesis is explained from the research I conducted in which I learned that the curdling process of milk happens as a result of the changes in the structure of the milk protein, or casein, from the changes in the pH of the milk. Adding lemon juice changes the acidity of the milk and therefore causes the milk to curdle. As the protein structure of milk changes due to acidification, the casein begins to coagulate. However, the best form of milk to use is fresh, raw milk because it contains bacteria that feed on the lactose, or the sugar in milk, to form lactic acid. Along with lactic acid, the acid added in acid coagulation of milk will produce larger quantities of curds. In the research, I also learned that cheese can be made from the milk of different mammals. These milks contain varying amounts of fat. In “Cheese Primer,” Steven Jenkins states that, “Fat is important to an individual cheese’s character, but less important overall, since cheese can be made from milk that is full fat or reduced fat, or from skim milk that has virtually no fat at all.” In his book, Jenkins also explains that, “On average, cow’s milk contains (by weight) about 87% water, 3½% protein, 3¾% fat, 5% lactose, along with water-soluble vitamins,…., and minerals…” Because of the permeability of the casein structure and the changes that occur to the structure of casein during acidification, the higher the fat content of the milk used, the more fat may be trapped in the clumps that form in the coagulation of the milk, which increases the percent of curds produced. Bibliography:

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Purpose The purpose of this project is to investigate the effect of different amounts of acid on the curdling process of milk. This will be accomplished by experimentation and comparative studies. This research will include information about the cheese making process, different types of milk used for cheese making, and the effect of acids on milk.

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Hypothesis For each of the different milk types, the more drops of acid that are added, the more curds will be produced. The higher the percent milk fat, the amount of curds produced will increase.

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Procedure For each of the different milk types, the following steps were followed. Divide the cups into sets of five and label 1, 2, 3, 4, and 5. Weigh the empty cups and record in journal. Add 3 1 / 3 cups of milk into saucepan and heat on stove top to simmer (195° F) while stirring with a whisk to avoid milk from burning. When 195° F is reached, remove saucepan from stove top and pour warm milk into each of the cups to the mark. Weigh cups again and adjust as necessary so that the weight of milk in all cups is 150 grams. Subtract the weight of the empty cups from the weight of the cups with the milk to provide the weight of the milk. Add 0, 15, 25, 40, and 55 drops of lemon juice to cups 1 through 5. Allow cups to cool for about 1 ½ hours. Meanwhile, cut the cheesecloth into equal sizes, and weigh each piece. After the milk has cooled, place a piece of cheesecloth (folded over once) into the strainer, and pour the milk over the cheesecloth so that the whey passes through, but the curds do not. Fold the cheesecloth containing the curds up from the corners, and hang the cheesecloth with a clothespin on the hanger to allow the whey to continue to drain out onto newspaper overnight. Weigh the cheesecloth with the curds. Subtract the weight of the cheesecloth to provide the weight of the curds obtained.

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Conclusion The results of my experiment are that the more lemon juice drops are added, the more curds are produced. Also, the higher the milk fat content of the milk there is, the more curds are produced.

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Journal Spiral or composition notebooks Keep a hand written journal to record day-today details of your project. Include description of what needs to be done to complete experiment. Can be put in the back pocket of binder

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Display Board Must be 91 cm tall, 121cm wide, and 30 cm deep All information is neatly typed and organized in professional manner. Must include 2 self-generated items, such as graphs, charts, models, pictures, or drawings. Must include: Title Purpose Hypothesis Materials Procedures Data Results Conclusion Abstract

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Oral Presentations Be prepared to present your project to the judges. Five to seven minute presentation including title and purpose, and summarizing procedures, data, results, and conclusion. Expect questions and answer with confidence. Demonstrate clear communication skills. Maintain eye contact. Display enthusiasm.